There is a demand for new methods of contraception than can provide protection against unintended pregnancies as well as reduce risk of venous thromboembolism (VTE), particularly for obese women. The mission of the CCTN is to develop protocols and conduct clinical trials that assist in providing effective and safe contraception in women.The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) has a mission to develop safe and effective contraceptives for women, including obese women. Obesity is the number one public health issue facing the US population and is an independent risk factor for venous thromboembolism (VTE). Therefore, there is a public health need to develop effective contraception for obese woman that does not increase the risk of VTE.